/*
 * Copyright (C) 2010 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.zxing.qrcode.decoding;

import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.ReaderException;
import com.google.zxing.Result;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.camera.CameraManager;
import com.google.zxing.qrcode.camera.PlanarYUVLuminanceSource;
import com.google.zxing.qrcode.ui.ShareCaptureActivity;

import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;

import java.lang.ref.WeakReference;
import java.util.Hashtable;

import org.apache.log4j.Logger;

final class DecodeHandler extends Handler
{
    
    private static final Logger log = Logger.getLogger(DecodeHandler.class);
    
    private final WeakReference<ShareCaptureActivity> mActivity;
    
    private final MultiFormatReader multiFormatReader;
    
    DecodeHandler(ShareCaptureActivity activity, Hashtable<DecodeHintType, Object> hints)
    {
        multiFormatReader = new MultiFormatReader();
        multiFormatReader.setHints(hints);
        mActivity = new WeakReference<ShareCaptureActivity>(activity);
    }
    
    @Override
    public void handleMessage(Message message)
    {
        ShareCaptureActivity activity = mActivity.get();
        if (activity == null) {
            return;
        }

        switch (message.what)
        {
            case HandlerMsg.MSG_DECODE:
                // Logger.d(TAG, "Got decode message");
                decode(activity, (byte[])message.obj, message.arg1, message.arg2);
                break;
            case HandlerMsg.MSG_QUIT:
                Looper.myLooper().quit();
                break;
        }
    }
    
    /**
     * Decode the data within the viewfinder rectangle, and time how long it took. For efficiency, reuse the same reader
     * objects from one decode to the next.
     * 
     * @param data The YUV preview frame.
     * @param width The width of the preview frame.
     * @param height The height of the preview frame.
     */
    private void decode(ShareCaptureActivity activity, byte[] data, int width, int height)
    {
        long start = System.currentTimeMillis();
        Result rawResult = null;
        PlanarYUVLuminanceSource source = CameraManager.get().buildLuminanceSource(data, width, height);
        BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
        try
        {
            rawResult = multiFormatReader.decodeWithState(bitmap);
        }
        catch (ReaderException re)
        {
            // continue
        }
        finally
        {
            multiFormatReader.reset();
        }
        
        if (rawResult != null)
        {
            long end = System.currentTimeMillis();
            log.debug("Found barcode (" + (end - start) + " ms):\n" + rawResult.toString());
            Message message = Message.obtain(activity.getHandler(), HandlerMsg.MSG_DECODE_SUCCEEDED, rawResult);
            Bundle bundle = new Bundle();
            bundle.putParcelable(DecodeThread.BARCODE_BITMAP, source.renderCroppedGreyscaleBitmap());
            message.setData(bundle);
            // Logger.d(TAG, "Sending decode succeeded message...");
            message.sendToTarget();
        }
        else
        {
            Message message = Message.obtain(activity.getHandler(), HandlerMsg.MSG_DECODE_FAILED);
            message.sendToTarget();
        }
    }
    
}
